Electrical contact mounting



June 28, 1960 R. VRADENBURGH 2,943,170

ELECTRICAL CONTACT MOUNTING Filed Feb. 21. 1958 Poesy? pane/mum yil/zgm fi n rrap/ver United States Patent ELECTRICAL CONTACT MOUNTING Robert Vradenburgh, Yonkers, N.Y., assignor to Ward Leonard Electric Co., Mount Vernon, N.Y., a corporation of New York Filed Feb. 21, 1958, Ser. No. 716,807

2 Claims. (Cl. 200-87) This invention relates to mountings for electrical contacts and particularly to the mounting of finger-type contacts in magnetic relays.

An object of this invention is to provide a mounting for electrical contacts that permits an assembly of the contact and mounting with a minimum of manipulative steps and results in a contact and mounting assembly that produces the desired action between the contact surfaces of the movable contact and the contact surfaces of the fixed contact.

Otherand further objects of the invention will become apparent from the following description taken in .connection with the drawings in which:

Fig. 1 is a sectional view of the finger contact in a disengaged position; I

Fig. 2 is a sectional view illustrating the contact and mounting in an engaging position;

Fig. 3 is a sectonal View taken along lines 33 of Fig. 1;

Figs. 4 and 5 are sectional views illustrating the assembly of the contact andspring on the insulating member; Fig. 6' illustrates a sectional view of another embodiment of the invention taken through the mounting pin;

Figs. 7 and 8 illustrate other embodiments of the mounting; and

Fig. 9 illustrates the mounting used on a contact having a straight line motion.

The contact mounting 10 may be secured to an armature 11 which is pivotally supported by a hinge 12. The

mounting member 10 comprises a panel 13- having ametallic finger-type contact :14 mounted thereon to move in and out of engagement with a'fixed contact 15. The contact 14 has a button contact 14a forming contact means for engaging a fixed contact. The relay is not illustrated and any well-known type of relay maybe used in connection with the contact and mounting. The armature may be positioned in relation to the magnet so that the movable contact :14 may be moved in or out of contact with the fixed contact on energization or deenergization of the magnet, depend-ing upon the type of relay. In the embodiment illustrated, the armature carries the hinged member 12. However, the hinged member 12 may be secured tolthe mounting member 10 depending upon the particular requirements of the relay.

This invention is directed to the mounting of the finger-type contact 14 on the panel 13. The panel 13 may be molded from any suitable electrically insulating plastic material and has a pin 16 integrally molded therewith and extending normal to the panel 13 to project through a slot 23 in the finger type contact. As illustrated in Figs. 1-3, the pin has a tapered portion or stem 18 with ahead '19 forming a circumferentially extending shoulder: 20. The finger-type contact fits over the head 19 and. the conical portion 18 and normally seats fiat in contact with the upper surface of the panel 13. I conically shaped helical spring 25 is positioned to engage the shoulder 20 and the upper surface of the contact 14 to hold the contact in the normally flat position. An electrical lead may be secured to the contact by means of the rolled or cylindrically shaped lugs 21 and 22 turned up at the end of the contact 14. These lugs may be positionedand secured to the contact at other locations in any well-- known manner. The contact 14 has a rectangularl} shaped slot 23 which has a length greater than the base of the pin to permit a longitudinal sliding of the contact 14 in relation to the panel 13. The rectangular opening 18 also longer and wider than the head 19 so that the contact can be readily fitted over the pin. A projection extending normal to the contact 14 fits in an opening 26 in the panel 13 to limit the movement of the contact finger 14 and to form a pivoting means for the contact when lifted 011 the panel.

The width of the slot 23 is slightly larger than the diameter of the base of the pin and limits the sidewise movement of the contact. On actuation of the mounting means 10 the finger 14 is tilted and brought into engagement with the fixed contact 15. As the armature further moves, the panel 13 is drawn down and the finger contact 14 engages the fixed contact and pivots to raise the finger off of the top of the panel and to compress the spring 25. The projection 24 engages the back of the opening 26 and the force against the contact button rotates the contact about this engaging point to lift the contact. This compressive force imparts a longitudinal movement to the contact resulting in a wiping contact action between the movable contacts and the fixed contacts. On the separation of the contacts the movable contact is again moved laterally to produce a wiping action and then reseats flat on the top of the panel 13.

The contact is assembled on the insulating member by fitting the contact 14 over the pin 16 by means of the slots 23. The helical spring is then fitted over the pin 16.v The inner diameter of the upper helical Winding of the spring is less than the outer diameter of the head and greater than the diameter of the upper portion of the conical section. As the smaller upper turn is forced over the head it expands and after passing thereover it snaps underneath the head and engages the shoulder 20. In Figs. 1-5 the pin 16 is illustrated as being molded as part of the panel. However, instead of being molded, separate pins may be secured by fitting in a hole 27 and secured in place by means of the bolt 28. It is thus seen that the finger contact may be mounted on the insulating member by means of two steps: one, fitting the contact over the pin and, two, fitting the pin and snapping it in, place in engagement with the contact and head.

In Figs. 7 and 8 other embodiments of the invention are illustrated. In Fig. 7 a relay is schematically illustrated with a supporting frame 30, a magnet 31 and a. pair of fixed spaced contacts 32 and 33 mounted on a supporting arm 34; The relay has an L-shapcd armature 35 of magnetic material pivotally mounted on an L- shaped support 36. The contact finger 37 has a genengage the fixed contacts 32 and 33. The armature andv contact are secured to the L-shaped support 36 by means of cylindrical pin with a head 41. The pin 40 is secured to the support 36 by means of a rivet or bolt 42 extending through the support 36 and fastening inside the pin'40. The pin 40 may extend through the support and be turned over or flattened, as illustrated in Fig. 9. The pin 40 extends through slots 43 and 44 in the armature portion 35b and the contact portion 37b, respectively,; and is pressed into engagement by means of the comically; shaped helical spring 45 fitting over the head 41 and press-i ing against the portion 37b of the contact. The armature has spaced projections 47 for pivotally relating the Patented June 28, 1960 contact 37 to the armature. Thus, the mounting means formed by the pin 40 and the spring 45 resiliently holds the contact and armature to the support 36 so that the armature engages the support 36 at the pivot point and the contact 37 at the projection 47 and at the ends of the portions 35b and 3719. On actuation of the armature the. armature rotates the contact 37 out of contact with the fixed contact 32 and into contact with the fixed contact 33 through a portion of the rotation. On continued rotation of' the armature the projection 47 disengages from the contact 37 and the armature presses the contact at the engaging ends to produce a wiping action between the hut-ton. contact 3-9 and the fixed contact 33. Thus, the mounting means disclosed herein produces a proper fastening of the armature and contact to the frame of the relay.

In Fig. 8 another embodiment of the invention is shown in which a relay has an L-shaped frame 50 and a magnet 51. An armature 52 is pivotally mounted on the frame 50 and is resiliently held in position by the aforesaid mounting means which comprises a pin 53 secured to the projection 54 extending at an angle to the frame 50- by means of the bolts or rivets 55. In this form the pin 53 extends normal to the projection 54 and through a slot 56 in the portion 57 extending at an angle to the armature 52. The pin 53 has a head 58 with a conically shaped helical spring fitting under the head and pressing against the portion 57' of the armature 52 to. maintain the contact 60 in engagement with the fixed contact 61. The contact 60 is mounted on an arm 62 which may be resiliently mountedon the insulating panel 63 in any suitable and well-known fashion. The panel- 63. firmly secured to the armature 52 and moves therewith, and on actuation of movesthe finger. 62 andv contact 60 into engagement with the fixed contact 64 compressing the spring 59. In the case of a single pole relay. where an insulating panel is not required the pin may be cast or subsequently fastened to the armature and the contact and spring fitted thereon in a manner similar to that previously described in connection with Figs. 4 and 5. Also,'the mounting may be used on contacts which move in a straight line motion such as those actuated by a solenoid type of relay or contactor.

In Fig. 9 the movable bridging contact 73 is mounted on the movable member 74 by means of the opening 7 3a fitting over the pin 75. The pin 75 has a stem 76, av head. 77 and a lateral flange 76a. A helical spring 78 is positioned between the head and the contact 73 to hold it resiliently on the movable member and to hold the pin 75 in place. The spring has turns with an inside diameter greater than the outside diameter of the head 77 to fit over the head 77 and an end turn with an insiderdiameter less than the outside diameter of the pin-to snap-overthe head and seat thereagainst. 'The end turn preferably-has an outside diameter approximately equal to the outside diameter of the head. As in the previous embodiment, the contact may be fitted over the pin 'and the spring snapped on to resiliently hold the contact. As the member 74 moves downward, the fixed contacts 80 and 81 are engaged and the continued movement causes the contact 73 to compress the spring to ensure a proper contact pressure. The pin may be molded asga single piece with the member 7 4, as in the embodiment of Fig. 1, or it may be formed as a separate pin fastened by. a rivet or a turned end. The pins in the embodiments ofFigs. 1, 4, 6, 7 and 8 may also be of a loose or separate construction with the spring supporting the pin.

The spring may be cylindrical in shape with restricted turnsat one end for fitting under the head of the pin and, as indicated, the pin may have various shapes, such as cylindrical or conical. The spring may also have restricted turns at both ends as long as the lower turns have a diameter greater than the width of'the slot 23 in the'eontact.

the armature 52. the panel 63 A feature of the invention is that the pin may be molded as a single piece with the panel and the contact may be fitted and secured in place by fitting it over on top of the pin and snapping the spring down over the head of the pin. There are only three parts forming the assembly: an insulated panel with molded pin, a helical spring and a contact finger. Only two manipulative steps are necessary for assembling these parts: one, fitting the contact over the pin and, two, snapping the spring in place. If aseparate pin is used, a-third operation of fitting the pin in the panel must be performed. The pin may be fitted in the opening in the panel by a forced fit or secured thereto by a bolt or rivet as indicated in the drawings. In either form the manipulative steps are at a minimum which substantially reduces the cost of assembling the relay. Although a single contact is illustrated in the drawings, it will be appreciated that most relays have at least two and many have four or six contacts per relay, thereby producing a substantial saving in View of the number of contacts used.

Various modifications and changes may be made iii-the,

invention without departing from the scope of the claims.

I claim: 1. In an electromagnetic type relay having-an energizable magnet and a pivotally mounted armature resiliently biased in spaced relation to said magnet and movingthrough an arc onactuation thereof, the combination of] an insulating member having a pin integral therewith and immovable in relation thereto, said pin having a stem with a base portion attached to said insulating member and an; end portion with a head, said head being larger than said end portion of said stem to form a shoulder facing said insulating member and spaced therefrom, afinger-type contact having an opening larger than said head and said base portion of said stem and fitting thereover to set on said insulating member, said finger-type contact having contact means at one end and having means for pivotally mounting said'finger-type contact on the insulating member at the other end to move said finger-type contact and said contact means through an arc in relation to said insulating member, a helical spring positioned between said shoulder and said contact, said spring having a turn larger than said head and said base portion and engaging said finger-type contact and having a second turn with an outside diameter approximately equal to the largest lateral diameter of the head to permit the fitting of said spring over said head and the snapping of said second turn over said head to engage said shoulder and resiliently press said finger-type contact against said insulating member.

2. In an electromagnetic type relay having a frame" with an armature pivotally mounted thereon for moving a contact through an arc, .the combination of a pinintegrally and immovably mounted on said frame, an open-g ing in said armature through which said pin extends, said.

pin having a head on the opposite side of said armature from said frame and having the largest lateral dimension;

smaller than said opening in said armature, said head forming a shoulder facing said armature, a helical spring having a first turn larger than said opening and said head engaging said armature and having a second turn with an' outside diameter approximately equal to the largest lateral dimension of said head to fit over said head and engage said shoulder to resiliently hold said spring between said" head and said armature for resiliently biasing said armae ture in a given position.

References Cited in the file of this patent UNITED STATES PATENTS 1,692,604 Whittingham Nov. 20, 1928; 1,751,444 Cohn et al Mar. 18, 1930 2,092,478 Sommermeyer Sept. 7, 1937 2,277,111 Johnson Mar. 24, 1942;: 2,517,052 Swinehart Aug. 1, 1950: 2,619,569 Savage Nov. 25, 1952 

